Treatment of cellulose esters for dyeing



Patented Apr. 7, i925,

rates I "rant nronenn METZGER, on nnrnntenne, enmaenv, Assren'oa ro nenrscnn Amtma SODA-FABRKK, or nunwresnanEn-on-rHn-nmnn, GERMANY, a. coneoaatrron or GEM.

i TREATMENT OF CELLULOSE ESTEIRS FQR DYEING.

No Drawing.

To all whom it may concern:

Be it known that l, RICHARD Mn'rzonn, citizen of the German Empire, residing at Heidelberg, Germany, have invented new and useful Improvements in the Treatment of Cellulose Esters for Dyeing, of which the following is a specification.

It is known that cellulose esters, especially cellulose acetate, have a limited capacity for taking up coloring matters. Various suggestions have already been made to remove this drawback, such as an addition of glycerol acetate or other organic acid esters of glycerol to the cellulose esters or to the dye-baths. Such compounds however have a dissolving effect on cellulose ester and are therefore liable to attack or destroy the fibres and articles made from them.

,1 have now discovered that the capacity of cellulose esters for taking up dyestuffs can be considerably increased Without any injurious action by treating them with a bath containing a dissolved ester of amineral oxygen acid, especially salts of acid esters of a mineral oxygen acid. Salts of acid esters of sulfuric or phosphoric or boric acid may be cited as examples. The said esters, or ester salts, may be used in a separate bath applied to the fibre, or article, preparator to'the dyeing or they may be added to the dyeing bath. The treatment may be done either at ordinary or elevated temperature. For example very good results are obtained when the fibre is put into an aqueous solution containing a compound of the aforesaid character and allowing it to stand for quite a while at ordinary temperature.

The following examples serve to further explain the nature of the invention but ,the

invention is not restricted to these examples,

[Em-ample 1.

1O kilogramines of celullose acetate silk phosphate Application filed Qctbbcr is, 1924'. Serial no. 'ieaaee.

diamond green B in a bath slightly acidulated with acetic acid.

Example 2.

1O kilogrammes of cellulose acetate silk are dyed, While gradually raising the temperature from 40 degrees up to 70 degrees centigrade, in a bath containing 200 litres of water, 100 grammes of auramine II, a little acetic acid and 6 kilogrammes of a 30 per cent aqueous solution of sodium dicresyl phosphate.

Example 3.

1 .kilogramme of cellulose acetate silk is handled for about 10 minutes in 30 litres of a 5 or 6 per cent solution of sodium dicresyl in water. This preliminary treatment may take place either at ordinary or elevated temperature. The silk is then wrung out, stretched and dyed with 0.8 per cent of methyl violet 213 extra at from 40 degrees to 70 degrees centigrade with or without an addition of purified waste sultite cellulose liquor. Thefibre prepared as before described may also be dyed with 1 per cent of azofiavine HS in a bath weakly acidulated with acetic acid.

Example 4.

out an addition of a protective colloid in a' dyebath containing, in each litre, 3 cubic centimetres of caustic soda lye. of. 40 de grecs Baum, 2 grammes of sodium hydrosulfite concentrated powder and 10 grammes of calcined Glaubers salt at a temperature of 10 degrees centigrade.- Thensoap as usual.

What I claim is:

1. The process of treating cellulose esters I for dyeing which consists in treating the cellulose esters in a bath containing an ester of a mineral oxygen acid.

2. The process of treating cellulose acetate for dyeing which consists in treating the cellulose ester in a bath containing a salt of an acide ester or" a mineral oxygen acid.

3. The process of treating cellulose acefate for dyein which consists in treating the fibre in a, iath containing a salt of an. acid ester of phosphoric acid.

4. The process of treating cellulose ecetate fibre for dyeing which consists in treeting the fibre in a bath containing a salt of an acid ester of phosphoric acid and subse meets? my hand.

RICHARD METZGER. Attest:

A. H. GERNERT, JANE GINsTI. 

